热带不同植被边坡水文效应室内模型试验

结合海南地区台风强降雨规律,对三种植被条件的粉土边坡模型进行了人工降雨试验,为热带生态护坡的植被选择提供依据。通过测量两次降雨过程中的总降雨量、地表径流量、雨水渗出量、坡体储水量及相应时间,对三种植被条件边坡的水文效应开展了分析。相较于裸土边坡,细叶结缕草边坡和肾蕨边坡均具有较好的抗雨水冲刷能力,肾蕨边坡更占优势。降雨前后,裸土边坡渗透性大幅降低；细叶结缕草边坡渗透性有所下降,但不明显；肾蕨边坡渗透性则显著提高。肾蕨边坡良好的储水持水能力在一般情况下是有利于边坡稳定的,但在长期干旱后遭遇强降雨时,也有可能因其储水能力太强而给边坡稳定带来不利影响。相比之下,裸土边坡和细叶结缕草边坡的储水和持水能力均较差。综合比较来看,一般情况下,肾蕨的水文效应对于保持边坡的稳定性是最有利的。

Laboratory Model Test on Hydrologic Effect of Slope with Different Plants in Tropical Region

Combined with the heavy rainfall pattern of typhoon in Hainan, artificial rainfall experiment was conducted on silt slope model with three vegetation conditions to provide basis for vegetation selection in tropical ecological slope protection. The hydrological effects of three vegetation slopes were analyzed by measuring the total precipitation, surface runoff, rainwater seepage, water storage in slope, and corresponding time during two rainfall processes. Compared with bare soil slope, both of Zoysia japonica slope and Nephrolepis auriculata(L.) slope have better ability of resisting rain wash, and the latter is more dominant. Before and after rainfall, the permeability of bare soil slope is greatly reduced, which is declined but not obvious of Zoysia japonica slope and significantly improved of Nephrolepis auriculata(L.) slope. In general, good water storage and water retention capacity of Nephrolepis auriculata(L.) slope is conducive to the stability of slope, but it may also bring adverse effects on slope stability when heavy rainfall after a long period of drought because of its strong water storage capacity. In contrast, both of bare soil slope and Zoysia japonica slope have poor water storage and water retention capacity. Compared comprehensively, in general, Zoysia japonica is the most favourable choice to maintain the stability of slope.